<?php
/**
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * @author Eddie Drapkin <eddie@frameweld.com>
 * @license http://www.gnu.org/licenses/lgpl-3.0.txt
 * @package Solphr
 * @subpackage Query
 * @version 0.1-pre
 */

/**
 * Interface for all "datatypes" that wind up going into a Solphr transaction before
 * be sent off into the blue horizon.  Mostly used for type hinting / interface enforcing.
 * @author Eddie Drapkin <eddie@frameweld.com>
 * @license http://www.gnu.org/licenses/lgpl-3.0.txt
 * @package Solphr
 * @subpackage Query
 */
interface Solphr_Query_Interface {
	/**
	 * Returns a valid Solr query expression. 
	 * @return string The query item that the instance translates to.
	 */
	public function __toString();
}